A siphon is a very effective means for transferring fluid from one container to another. However, the reliable starting of the siphon action especially when the fluids to be transferred are hazardous has proved to be difficult. LOW in U.S. Pat. No. 310,863 discloses an effective device for siphoning from casks which includes a plug having a pressurizing tube and a siphoning tube passing therethrough. The Low device is only effective if the casks have uniformly sized, circular bung holes so that the frustroconical rubber plug can easily form a good seal therewith. In addition, Low provides means so that the pressurizing tube can be bent over to restrict the flow out of the siphon tube. STANSBURY discloses U.S. Pat. No. 314,487 an improvement over the Low device by providing a frustroconical plug with a sealed ring therearound to improve the sealing action, but at the same time restrict the use of his plug to openings of a specific size. At the same time, Stansbury provided a spring clip arrangement on the pressure tube to block it off when not manually biased to the open position during pressurizing of the liquid container. FLEINER, in U.S. Pat. No. 523,739 discloses a similar device which is meant to be placed in the receiver container. The second tube thereof which physically corresponds to the pressurizing tube of the aforementioned devices is used to produce a reduced pressure within the receiving container to start the siphon action. In LEE, U.S. Pat. No. 915,867, a prime retainer device is employed on the siphon tube which along with a pressurizing tube passes through a frustroconical stopper. As can be seen in the above discussed prior art, the stopper or plug is the weak link, it being required to fit snuggly through its own natural resilience to assure a seal with a container opening since the stopper must necessarily be self-supporting. The two requirements of self-supporting and providing a good seal with various size openings has made such devices suitable only when specifically applied to a narrow range of circular openings. Therefore, there has been a need for a siphon device which can be started easily in a relatively closed container which may have an opening over a wide range of sizes and other than a circular shape.